From 1333f218ed2a40df44fd88e892f76834f68f3444 Mon Sep 17 00:00:00 2001
From: Stephen Toub <stoub@microsoft.com>
Date: Thu, 22 Apr 2021 16:17:19 -0400
Subject: [PATCH] Add MetadataUpdateHandler to WinForms to repaint all open
 forms

---
 .../Internal/WinFormsMetadataUpdateHandler.cs | 26 +++++++++++++++++++
 1 file changed, 26 insertions(+)
 create mode 100644 src/System.Windows.Forms/src/System/Windows/Forms/Internal/WinFormsMetadataUpdateHandler.cs

diff --git a/src/System.Windows.Forms/src/System/Windows/Forms/Internal/WinFormsMetadataUpdateHandler.cs b/src/System.Windows.Forms/src/System/Windows/Forms/Internal/WinFormsMetadataUpdateHandler.cs
new file mode 100644
index 00000000000..fbe85b20945
--- /dev/null
+++ b/src/System.Windows.Forms/src/System/Windows/Forms/Internal/WinFormsMetadataUpdateHandler.cs
@@ -0,0 +1,26 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System.Reflection.Metadata;
+using System.Windows.Forms;
+
+[assembly: MetadataUpdateHandler(typeof(WinFormsMetadataUpdateHandler))]
+
+namespace System.Windows.Forms
+{
+    /// <summary>Handle notifications of metadata updates being applied.</summary>
+    internal static class WinFormsMetadataUpdateHandler
+    {
+        /// <summary>Invoked after a metadata update is applied.</summary>
+        /// <param name="types">The list of types known to be updated, or null if it couldn't be determined.</param>
+        internal static void AfterUpdate(Type[]? types)
+        {
+            // Repaint all open forms.
+            foreach (Form openForm in Application.OpenForms)
+            {
+                openForm.BeginInvoke((MethodInvoker)(() => openForm.Refresh()));
+            }
+        }
+    }
+}